JPH05216280A - Negatively chargeable toner for electrostatic charge image development and developing method - Google Patents

Abstract

PURPOSE:To provide negatively chargeable toner possible to obtain a high density and high quality image for a long time by containing a specific quaternary ammonium salt or quaternary phosphonium salt compound as a negative charge-controlling agent to control filming of toner on a developer carrier. CONSTITUTION:In a negatively chargeable toner for electrostatic charge image development containing a binding resin, a coloring agent and the negative charge controlling agent, the quaternary ammonium salt compound expressed by formula I is contained as the negative charge controlling agent. (In the formula I, each of R<1>-R<4> is H or organic group and at least one of R<1>-R<4> is 1-69C and 3-66F linear or branched fluorine-containing alkyl group or alkenyl group.) When the toner is applied to nonmagnetic one-component developing process of electrophotography, the charged toner is uniformly carried on the developer carrier and is stably transported to developing zone. The same effect is also obtained by using a quaternary phosphonium salt compound expressed by formula II.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic recording,
The present invention relates to a novel negatively chargeable toner for developing an electrostatic charge image (electrostatic latent image) in electrostatic printing and a developing method using the toner.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electronic copying machine, a printer or a facsimile, which forms an electrostatic latent image on a latent image carrier and visualizes it with a developer to obtain a recorded image, a powdery material is used. A dry developing device using a developer is widely adopted.

As the powdery developer, a two-component type developer containing a toner and a carrier and a one-component type developer containing no carrier are known, and the former two-component type developer is used. The two-component development method can obtain a relatively stable and good recorded image, but on the other hand, deterioration of the carrier and variation of the mixing ratio of the toner and the carrier are likely to occur, maintenance of the apparatus is complicated, and the structure of the entire apparatus is large. It has a drawback that it is easy to change.

From this point of view, a one-component developing system using a one-component developer which does not have the above-mentioned drawbacks has been attracting attention. The one-component developer consists of toner only,
In some cases, an auxiliary agent is externally added to this if necessary. As the toner, there are a magnetic toner in which magnetic powder is kneaded into each toner particle itself, and a non-magnetic toner containing no magnetic substance. Here, since the magnetic substance is generally opaque,
When a color image including full color and multi-color is formed with magnetic toner, the developed visible image becomes unclear, and a vivid color image cannot be obtained. Therefore, especially for color development, it is desirable to adopt the one-component development method using non-magnetic toner.

By the way, in a developing device adopting a one-component developing system, a one-component developer is carried on a developer carrier and conveyed, and the developer carrier and the latent image carrier face each other. In the area, the electrostatic latent image formed on the latent image carrier is visualized by a developer, but in order to form a high-quality visible image of a predetermined density, a large amount of sufficiently charged toner is used. It is necessary to convey the latent image into a visible image by transporting the latent image to the developing area.

When a magnetic toner is used, the magnetic force of a magnet provided in the developer carrier can be utilized to carry the one-component developer on the carrier, so that the above-mentioned requirements are relatively easy. It is possible to meet

However, when a non-magnetic one-component developer is used, it cannot be carried on the developer carrying member by magnetic force, so that it is difficult to satisfy the above requirements. Various countermeasures against this have been proposed in the past,
For example, in Japanese Unexamined Patent Publication No. 61-42672, a dielectric material (insulator) layer is laminated on the surface of a developer carrying member (developing roller), and a developer supplying member including, for example, a sponge roller. Are pressed against each other to frictionally charge them with opposite polarities, and the non-magnetic toner charged with the opposite polarity to this dielectric is electrostatically attached to the dielectric, and the one-component developer is conveyed to the developing area. The method to do is proposed.
However, even by this method, the strength of the electric field formed in the vicinity of the dielectric surface cannot be sufficiently increased,
It is difficult to carry a large amount of toner on the surface of the developing roller, the amount of developer that can be conveyed to the developing area is insufficient, and it is difficult to form a high-density visible image.

A configuration is also known in which an electric field is applied between the developing roller and the developer supplying member in such a direction that the non-magnetic toner is electrostatically transferred to the developing roller side, but such a configuration is added. However, it is difficult to attach a sufficient amount of toner to the developing roller.

As the toner supply member, 10 ² to
Conductive foam of 10 ⁶ Ω · cm (JP-A-60-2290)
57), an elastic body with a skin layer (JP-A-60-229).
No. 060) and fur brush (JP-A-61-426).
No. 72) and the like, and as a developing roller, a metal body having irregularities on the surface (JP-A-60-53976) and an insulating coated roller body (JP-A-55-46768). JP-A-58-132768), an electrode roller having an insulating surface and a conductive surface (JP-A-53-36245), and the like.

Further, in a developing device using a non-magnetic one-component developer, a sponge roller is disclosed in JP-A-60-229057, an elastic roller is disclosed in JP-A-62-229060, and a developer roller is disclosed in JP-A-61-52663. A fur brush or the like is used to apply an electric charge to the toner by frictional electrification between the toner and the replenishing member, and the toner is electrostatically attached to the developing roller by friction during contact with the developing roller. The layer thickness regulating member is used to control the toner layer to develop the latent image on the photoconductor. Various materials such as an insulating material, a medium resistance material, and a laminated material are used as the material of the developing roller.

According to the methods disclosed in these documents, the toner is attached to the developing roller by friction between the toner replenishing member and the developing roller. Is difficult to obtain and, as a result, toner adhesion is insufficient.

Further, as shown in JP-A-54-51841, etc., after scraping off the one-component developer on the developing roller after passing through the developing area, the surface layer of this developing roller is scraped off. On the other hand, a technique has been proposed in which a corona discharge is performed to apply an electric charge, and then a non-magnetic toner is electrostatically and positively attached to a developing roller by a developer supplying member. The amount of developer carried on the surface of the developing roller cannot be increased, and a large amount of developer cannot be conveyed to the developing area.

As a method of solving these problems, the inventors of the present invention have previously described "a one-component system comprising a non-magnetic toner in which an auxiliary agent is externally added as necessary to a rotationally driven developer carrier. A developer is supplied, and the developer is carried on the surface of the carrier and conveyed, and the latent image carrier and the developer carrier are formed on the latent image carrier in the developing regions facing each other. In a developing method for visualizing an electrostatic latent image by the developer carried on a developer carrier, in the vicinity of the surface of the carrier by selectively retaining an electric charge on the surface of the developer carrier. An image in which a large number of minute closed electric fields are formed, the charged toner is attracted by the closed electric fields, and the developer is made to adhere to the surface of the developer carrier and carried, and the electrostatic latent image is visualized by the carried developer. Forming method "was proposed.

In such a method, a large number of minute closed electric fields (microfields) are formed in the vicinity of the surface of the developer carrying member, so that the electric field strength can be remarkably increased as compared with the conventional method, and a sufficiently charged large amount of electric field can be obtained. It has many advantages such that the toner of (1) can be carried on the developer carrying member and conveyed to the developing area.

However, according to the subsequent studies by the present inventors, in the developing method in which a large number of minute closed electric fields (microfields) are formed near the surface of the developer carrier as described above, the developer carrier is It is difficult to always stabilize the above toner layer with two or more layers, the toner layer becomes thin and the amount of developed toner decreases, the density of the image area becomes low, and the toner layer becomes uneven. Therefore, uneven development may occur or fogging may occur, and further, a filming phenomenon often occurs on the developer carrying member,
It has been found that the microfield effect is reduced, the amount of toner held on the developer carrying member is reduced, and it becomes difficult to sufficiently develop the toner on the latent image carrying member.

The present invention has been made in view of the above-mentioned conventional circumstances, and an object thereof is to develop a sufficiently charged toner in the image forming method by the general non-magnetic one-component developing system described above. The toner can be uniformly carried on the developer carrier and conveyed to the development area, and the filming of the toner on the developer carrier is controlled, so that a high-density and high-quality image can be obtained over a long period of time. To provide a toner and a developing method using the toner.

[0017]

As a result of intensive studies, the present inventors have found that a quaternary ammonium salt or a quaternary phosphonium salt containing a binder resin and a colorant and further serving as a negative charge control agent. We have found that a toner containing a salt compound is suitable for the above purpose, and completed the present invention.

That is, according to the present invention, a negative charge toner for developing an electrostatic charge image, which comprises at least a binder resin, a colorant and a negative charge control agent, is represented by the following general formula 1 as the negative charge control agent. There is provided a negatively charged toner for developing an electrostatic charge image, which comprises at least one kind of a quaternary ammonium salt compound.

[Chemical 1] (In the formula, R ^{1 to} R ⁴ represent a hydrogen atom or an organic group, and at least one of R ^{1 to} R ⁴ may have a linking group and has 1 to 69 carbon atoms and 3 to 66 fluorine atoms. A linear or branched fluorine-containing alkyl group or a fluorine-containing alkenyl group, and up to three of R ^{1 to} R ⁴ are branched alkyl groups, alkenyl groups, aryl groups or arylalkyl groups,
X ⁻ represents an organic or inorganic anion. )

Further, according to the present invention, in a negative charge toner for developing an electrostatic charge image, which comprises at least a binder resin, a colorant and a negative charge control agent, the negative charge control agent is represented by the following general formula 2. There is provided a negatively chargeable toner for developing an electrostatic charge image, which comprises at least one kind of a quaternary phosphonium salt compound.

[Chemical 2] (In the formula, R ^{1 to} R ⁴ represent a hydrogen atom or an organic group, and at least one of R ^{1 to} R ⁴ may have a linking group and has 1 to 69 carbon atoms and 3 to 66 fluorine atoms. A linear or branched fluorine-containing alkyl group or a fluorine-containing alkenyl group, and up to three of R ^{1 to} R ⁴ are branched alkyl groups, alkenyl groups, aryl groups or arylalkyl groups,
X ⁻ represents an organic or inorganic anion. )

Further, according to the present invention, a one-component developer consisting of toner particles is supplied and carried on a developer carrying member provided so as to face the electrostatic latent image carrying member, and the one-component developer is carried by the carried toner particles. In the developing method for developing the electrostatic latent image, the toner particles are used as a negative charge control agent and a quaternary ammonium salt compound represented by the following general formula 1 and / or a quaternary phosphor represented by the following general formula 2. There is provided a developing method comprising a phonium salt compound.

[Chemical 1] (In the formula, R ^{1 to} R ⁴ represent a hydrogen atom or an organic group, and at least one of R ^{1 to} R ⁴ may have a linking group and has 1 to 69 carbon atoms and 3 to 66 fluorine atoms. A linear or branched fluorine-containing alkyl group or a fluorine-containing alkenyl group, and up to three of R ^{1 to} R ⁴ are branched alkyl groups, alkenyl groups, aryl groups or arylalkyl groups,
X ⁻ represents an organic or inorganic anion. )

[Chemical 2] (In the formula, R ^{1 to} R ⁴ represent a hydrogen atom or an organic group, and at least one of R ^{1 to} R ⁴ may have a linking group and has 1 to 69 carbon atoms and 3 to 66 fluorine atoms. A linear or branched fluorine-containing alkyl group or a fluorine-containing alkenyl group, and up to three of R ^{1 to} R ⁴ are branched alkyl groups, alkenyl groups, aryl groups or arylalkyl groups,
X ⁻ represents an organic or inorganic anion. )

The negative charge toner for developing an electrostatic charge image of the present invention contains the above-mentioned specific quaternary ammonium salt or quaternary phosphonium salt compound as a negative charge control agent. When used in an image forming method based on a non-magnetic one-component developing method, a sufficiently charged toner can be uniformly carried on the developer carrying member and stably conveyed to the developing area, and at the same time, to the developer carrying member. The toner filming is controlled, and high-density and high-quality images can be obtained for a long period of time.

In the toner used in the present invention, as described above, the quaternary ammonium salt compound represented by Chemical formula 1 or the quaternary phosphonium salt compound represented by Chemical formula 2 is used as a negative charge control agent. However, specific examples of the quaternary ammonium salt compound in this case include the compounds shown in Table 1 below.

[0023]

[Table 1- (1)]

[Table 1- (2)]

Specific examples of the quaternary phosphonium salt compound used as the negative charge control agent in the toner of the present invention include the compounds shown in Table 2 below.

[0025]

[Table 2- (1)]

[Table 2- (2)]

[Table 2- (3)]

As the binder resin used in the toner used in the present invention, all the binder resins conventionally used as toner binder resins are applicable. Specifically, a homopolymer of styrene such as polystyrene, polychlorostyrene, and polyvinyltoluene or a substitution product thereof; styrene /
p-chlorostyrene copolymer, styrene / propylene copolymer, styrene / vinyltoluene copolymer, styrene / vinylnaphthalene copolymer, styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer,
Styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer,
Styrene / butyl methacrylate copolymer, styrene / α
-Methyl chloromethacrylate copolymer, styrene / acrylonitrile copolymer, styrene / vinyl methyl ether copolymer, styrene / vinyl ethyl ether copolymer, styrene / vinyl methyl ketone copolymer, styrene / butadiene copolymer, Styrene / isoprene copolymer, styrene / acrylonitrile / indene copolymer,
Styrene-based copolymers such as styrene / maleic acid copolymers and styrene / maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyvinyl butyl butyral, Polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin,
Aromatic petroleum resins, chlorinated paraffins, paraffin waxes, etc. may be mentioned, and these may be used alone or in admixture of two or more.

As the colorant used in the toner used in the present invention, all of the pigments and dyes conventionally used as the colorant for toner can be applied. Specifically, carbon black, lamp black, iron black, ultramarine,
Nigrosine dye, aniline blue, chalco oil blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6C lake, chrome yellow, quinacridone, benzidine yellow, malachite green, malachite green hexalate, Examples thereof include oil black, azo oil black, rose bengal, monoazo dyes and pigments, disazo dyes and pigments, and trisazo dyes and pigments.

Further, in the toner used in the present invention,
In addition to synthetic waxes such as low molecular weight polyethylene and polypropylene to provide mold release properties, candelilla wax, carnauba wax, rice wax, wood wax, jojoba oil and other plant waxes; beeswax, lanolin, whale Animal waxes such as waxes; mineral waxes such as montan wax and ozokerite; oil-based waxes such as hydrogenated castor oil, hydroxystearic acid, fatty acid amides, and phenol fatty acid esters can be contained.

In the toner used in the present invention, in addition to the above-mentioned binder resin, colorant, etc., various plasticizers ( It is also possible to add auxiliary agents such as dibutyl phthalate and dioctyl phthalate) and resistance adjusting agents (tin oxide, lead oxide, antimony oxide, etc.). Further, the toner of the present invention may be mixed with additives other than the above-mentioned binder resin, colorant, auxiliary agent and the like, if necessary. Examples of the additive include a fluidizing agent such as colloidal silica, titanium oxide, and aluminum oxide.

The toner of the present invention is useful for image formation by a non-magnetic one-component developing system in electrophotography, and when applied to the system, a sufficiently charged toner is uniformly carried on a developer carrying member for development. The toner can be stably conveyed to the area, and the filming of the toner on the developer carrying member is controlled, so that a high-concentration and high-quality image is formed for a long period of time. In particular, in the toner of the present invention, a surface layer in which dielectric particles are dispersed on a conductive substrate containing an organic substance as a main component is formed on the surface of a developer carrier, and the charge is selectively retained. By this, a large number of minute closed electric fields are formed in the vicinity of the surface of the developer carrier, and a non-magnetic one-component developer comprising a toner to which an auxiliary agent is externally added is supplied on the developer carrier, It is useful for an image forming method in which an electrostatic latent image is visualized by the developer by a minute closed electric field. When the present toner is applied to the method, a large amount of sufficiently charged toner is deposited on the developer carrier. More than one layer can be stably and uniformly stacked and stably transported to the developing area, and the filming of the toner on the developer carrying member is controlled, so that a high-density and high-quality image can be formed for a long time. it can.

The image forming method will be described below. FIG. 1 shows an outline centering on a developer carrier portion of a typical developing device useful for carrying out this image forming method. Figure 1
In the toner tank 70, the toner 6
0 is a toner supply member (sponge roller or fur brush) 4 by a stirring blade (toner supply auxiliary member) 50.
The toner 60 is forcibly moved to 0, and the toner 60
0 is supplied. On the other hand, the developer carrying member (developing roller) 20 that has completed development rotates in the direction of the arrow (for example, 40
0 rpm) to reach the contact portion with the toner supply member 40.
The toner supply member 40 rotates in the opposite direction to the developer carrying body 20, charges the developer carrying body 20 and the toner 60, and attaches the toner 60 to the developer carrying body 20. Further, the developer carrying member 20 rotates, and the toner adhered on the developer carrying member 20 is removed by the toner layer thickness regulating member (elastic blade) 30.
The charge is stabilized while the thickness is controlled, and the developing area 80
Reach In the development area 80, the latent image is developed by contact or non-contact development. Here, if necessary, a bias voltage such as direct current, alternating current, direct current superimposed alternating current, or pulse is applied to the developer carrying member 20 and the toner supply member 40,
The optimal image can be controlled.

Next, the mechanism of toner adhesion to the developer carrier 20 of this type (electrode type) will be described. As an example of the developer carrying member 20, a dielectric portion and a conductor portion are mixed on the surface thereof in a minute area. If the shape is circular, the size of the area is
Diameter is 30 to 2000 μm, preferably 100 to 400 μm
Small areas of size m are randomly dispersed. The area ratio is preferably such that the area of the dielectric portion is 50 to 80%.

Toner adhesion is as follows. First, the developer carrying member 20 that has completed development rotates in the direction of the arrow and contacts the toner supply member 40. The residual toner in the non-image area that has not been developed is mechanically and electrically scraped by the toner supply member 40, and the dielectric portion is charged by friction. At this time, the charges of the developer carrier 20 and the toner due to the previous development are made constant by friction and initialized. Next, the toner carried by the supply member 40 is charged by friction and electrostatically adheres to the dielectric portion of the developer carrying member 20. At this time, the polarity of the toner is opposite to the charge of the photoconductor, and the dielectric portion of the developer carrying member 20 has the same polarity. The electric field on the developer carrying member 20 at this time becomes a microfield (closed electric field), and becomes an electric field having a large electric field gradient, so that the toner can be attached in multiple layers. Also, since the toner that adheres has a closed electric field,
The developer carrying member 20 is strongly pulled and is in a state of being hard to separate.

The toner layer thickness of the toner layer is further controlled by the toner layer thickness regulating member 30 and reaches the developing area 80. The electric field between the developer carrier 20 and the electrostatic latent image carrier (photoreceptor) 10 in the developing region 80 has a large electrode effect,
The toner on the developer carrying member 20 becomes an electric field that easily adheres to the electrostatic latent image carrying member 10, and development is performed.

Many kinds of developing device parts can be used, but the following is a selection of only preferable materials in terms of releasability from toner and durability. Toner supply member: Urethane type, acrylic type, weak plus type with fur brush. Layer thickness regulating member: An elastic member that can be pressed against, and a positive polarity resin layer such as a silicone resin is provided at the portion (blade) that comes into contact with the developer carrying member.

The developer carrier used in this method has a structure in which a surface layer made of a conductive material in which insulating particles are dispersed is formed on a conductive substrate. Is 10 ¹² Ω · cm or less, preferably 1
0 ⁸ Ω · cm or less of what can be used. Specifically, those obtained by adding a conductivity-imparting agent to organic polymers can be mentioned. In this case, organic polymers include resin materials (plastomers) and rubber materials (elastomers),
Specific examples thereof include the following.

Polyvinyl chloride, polyvinyl butyral,
Vinyl-based resins such as polyvinyl alcohol, polyvinylidene chloride, polyvinyl acetate, polyvinyl formal; polystyrene-based resins such as polystyrene, styrene / acrylonitrile copolymer, acrylonitrile / butadiene / styrene copolymer; polyethylene, ethylene / vinyl acetate copolymer Polyethylene resin such as coalescing; acrylic resin such as polymethylmethacrylate, polymethylmethacrylate / styrene copolymer; other polyacetal,
Polyamide, cellulose, polycarbonate, phenoxy resin, polyester, fluorine resin, polyurethane, phenol resin, urea resin, melamine resin, epoxy resin,
Plastomer materials such as unsaturated polyester resins and silicone resins.

Gen rubbers such as styrene / butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), nitrile / butadiene rubber (NBR), nitrile / isoprene rubber (NIR), chloroprene rubber (CR); butyl rubber (IRR) ), Ethylene / propylene rubber (EPM, EPDM), chlorosulfonated polyethylene (CSM), and other olefinic rubbers; epichlorohydrin rubber (CHR, CHC) and other ethereal rubbers; other silicone rubbers, fluorine rubbers, acrylic rubbers,
Elastomer materials such as urethane rubber and thermoplastic elastomers such as styrene type, olefin type, polyvinyl chloride type, urethane type, polyester type, polyamide type, fluorine type and chlorinated polyethylene type.

Further, as the conductivity-imparting agent, Ni, Cu
Metal powder such as; furnace black, lamp black,
Carbon black such as thermal black, acetylene black, channel black; tin oxide, zinc oxide,
Conductive oxides such as molybdenum oxide, antimony oxide, and potassium titanate; electroless plated products that are plated on titanium oxide, mica, etc .; inorganic fillers such as graphite, metal fibers, carbon fibers and surfactants, etc. Is mentioned. Furthermore, an organic ion conductor in which a metal ion is coordinated with a polymer matrix such as polyethylene oxide or polysiloxane can also be used.

When an elastomer is used among the above organic polymers as the conductive material, the surface layer of the developer carrying member has elasticity, and it is easy to make contact with the rigid drum-shaped photoreceptor. The use of conductive elastomers is particularly preferred, since contact development is greatly facilitated.

On the other hand, as the insulating particle material, 10 ¹³ Ω
-Cm or more, preferably 10 ¹⁴ Ω-cm or more is used. The average particle size is 5 μm or more,
It is preferably 10 μm or more. If it is less than 5 μm, it is difficult to form microfields, and stable toner adhesion and charging cannot be obtained. It does not matter whether it is a fixed form or an irregular form. Specific examples of these materials include inorganic particles such as alumina, berilia, magnesia, silicon nitride, boron fluoride, mullite, steatite, forsterite, zircon and cordierite, epoxy resin, fluorine resin and silicone. Examples thereof include organic particles such as resin.

When the conductive elastomer is used as the conductive material, it is preferable to use the elastomer as the insulating particles in order to further promote the low hardness. As the elastomer in this case, the same materials as those exemplified as the elastomer used for the conductive elastomer are used. Insulating elastomer particles can be produced by freezing the elastomer with dry ice or the like and then pulverizing it, pulverizing it with a grinder, and pulverizing it to form an aqueous emulsion using a surfactant and then curing it. A known method such as a method is adopted.

As the elastomer used for the conductive material and the insulating particles, silicone rubber is particularly preferable from the viewpoint of low hardness, environment resistance, releasability and the like. And
The negative charge control of the present invention is particularly effective when the surface of the developer bearing member is made of silicone rubber or resin, that is, the toner is sufficiently and stably controlled to be negatively charged. When this is applied to the microfield development method, a surface layer in which a dielectric silicone rubber or resin region is dispersed in a matrix of conductive silicone rubber or resin is provided on a conductive support. The body is used.

The amount of the insulating particles added to the conductive material is appropriately selected within the range of 10 to 200 parts by weight with respect to 100 parts by weight of the conductive material. The area of the surface insulating portion of the developer carrying member is preferably in the range of 20 to 60%, and the amount of insulating particles added is appropriately adjusted so as to fall within this range after the preparation of the carrying member.

[0045]

The present invention will be described in more detail with reference to the following examples. In addition, a part represents a weight part.

Example 1 Binder resin Styrene / acrylic copolymer 95 parts Release agent Low molecular weight polypropylene 5 parts Colorant carbon black 8 parts Charge control agent Exemplified compound (1) (provided that Rf = C ₈ H ₁₇ ) 3 parts

The mixture having the above composition was melt-kneaded, cooled, coarsely pulverized by using a hammer mill, and then finely pulverized by an air jet type fine pulverizer. The obtained finely pulverized product was classified to have an average particle size of 11 μm. 0.2 part of colloidal silica was added to 100 parts of the present particles and mixed to obtain a negatively charged toner of the present invention.

Next, 100 parts of silicone resin (SR-2411 manufactured by Torre Silicone Co.) and 100 parts of carbon black.
Part (Akzo Simmy Ketjen Black EC) 72
Master batch 1 made by milling with a ball mill for an hour
00 parts and silicone resin (SR-made by Torre Silicone Co., Ltd.
2411) 100 parts, 50 parts of silicon fine particles (Torefil E-850 manufactured by Toray Silicone Co., Ltd.) and 10 parts of toluene.
A coating solution was prepared with 0 parts, and the SUS roller was spray-coated with the coating solution, and a dried and polished developing roller was prepared. A developing device equipped with this developing roller was prepared, and the toner was attached to the developing device and an image was printed. As a result, a clear image with high image density and no background stain was obtained. Further, even after the continuous running of 5000 sheets, the toner is not filmed on the developing roller,
A clear image was maintained.

Example 2 Binder resin Styrene / acrylic copolymer 95 parts Release agent Low molecular weight polypropylene 5 parts Colorant carbon black 8 parts Charge control agent Exemplified compound (2) (provided that Rf = C ₈ H ₁₇ ) 3 parts

The mixture having the above composition was melt-kneaded, cooled, coarsely pulverized by using a hammer mill, and then finely pulverized by an air jet type fine pulverizer. The obtained finely pulverized product was classified to have an average particle size of 12 μm. 0.3 part of titanium oxide was added to 100 parts of the particles and mixed to obtain a negatively charged toner of the present invention.

Next, a developing device similar to that of Example 1 was prepared, the above toner was attached to the developing device, and an image was printed. As a result, a clear image with high image density and no background stain was obtained. .. Further, even after running 5000 sheets continuously, the toner was not filmed on the developing roller and a clear image was maintained.

Example 3 Binder resin Styrene / acrylic copolymer 95 parts Release agent Low molecular weight polypropylene 5 parts Colorant carbon black 8 parts Charge control agent Exemplified compound (21) 3 parts

The mixture having the above composition was melt-kneaded, cooled, coarsely pulverized by using a hammer mill, and then finely pulverized by an air jet type fine pulverizer. The obtained finely pulverized product was classified to have an average particle size of 12 μm. 0.5 part of colloidal silica was added to 100 parts of the present particles and mixed to obtain a negatively charged toner of the present invention.

Next, a developing device similar to that of Example 1 was prepared, and the above toner was attached to the developing device and an image was formed. As a result, a clear image with high image density and no background stain was obtained. .. Further, even after running 5000 sheets continuously, the toner was not filmed on the developing roller and a clear image was maintained.

Comparative Example Binder resin Styrene / acrylic copolymer 95 parts Release agent Low molecular weight polypropylene 5 parts Colorant carbon black 8 parts Charge control agent Chromium azo dye 2 parts

The mixture having the above composition was melt-kneaded, cooled, coarsely pulverized using a hammer mill, and then finely pulverized by an air jet type fine pulverizer. The obtained finely pulverized product was classified to have an average particle size of 12 μm. 0.5 parts of colloidal silica was added to 100 parts of the present particles and mixed to obtain a negatively-charged toner for comparison.

Next, a developing device similar to that of Example 1 was prepared, the above toner was attached to the developing device, and an image was printed. As a result, an image with high image density and no background stain was obtained. The image was poorly cut, and an image with a slightly poor resolution was obtained. This is probably because the charge amount is slightly low.

[0058]

INDUSTRIAL APPLICABILITY The negatively charged toner for developing an electrostatic image of the present invention comprises a quaternary ammonium salt compound represented by the above Chemical formula 1 or a quaternary phosphonium represented by the above Chemical formula 2 as a negatively charged control agent. Since this toner contains a salt compound, when this toner is applied to an image forming method using a non-magnetic one-component developing method, a sufficiently charged toner is uniformly carried on the developer carrier, and stable in the developing area. In addition to being conveyed, the filming of the toner on the developer carrying member is controlled, and a high-density and high-quality image can be obtained for a long period of time.

When the negatively charged toner of the present invention is used in the one-component developing method, a high-concentration and high-quality image is obtained, and in particular, a developer carrier having a surface made of silicone rubber or resin is used. The effect is high in some cases. Further, a surface layer having a structure in which a dielectric region is dispersed in a conductive surface is formed on a conductive support, and by selectively retaining an electric charge, a large number of minute closed electric fields are generated near the surface of the developer carrier. And a non-magnetic one-component developer consisting of a toner, to which an auxiliary agent is added externally, is supplied on the developer carrying member, and an electrostatic latent image is formed by the developer by the minute closed electric field. When applied to an image forming method for visualizing, a large amount of sufficiently charged toner can be stably and uniformly laminated on a developer carrying member in two or more layers, and can be stably conveyed to a developing area for a long period of time. Higher density and higher quality images can be obtained over the entire range.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view centering on a developer carrier part showing an example of a developing device useful for using the toner of the present invention, which forms an electric field of a microfield on the developer carrier.

[Explanation of symbols]

 10 Electrostatic latent image carrier 20 Toner conveying member 30 Toner layer thickness regulating member 40 Toner supply member 50 Stirring blade 60 Toner 70 Toner tank 80 Development area

Claims (4)

[Claims] 1. A negatively charged toner for developing an electrostatic charge image comprising at least a binder resin, a colorant and a negatively charged control agent, wherein the negatively charged control agent is a quaternary ammonium salt compound represented by the following general formula 1. A negatively chargeable toner for developing an electrostatic charge image, comprising at least one of [Chemical 1] (In the formula, R ^{1 to} R ⁴ represent a hydrogen atom or an organic group, and at least one of R ^{1 to} R ⁴ may have a linking group and has 1 to 69 carbon atoms and 3 to 66 fluorine atoms. A linear or branched fluorine-containing alkyl group or a fluorine-containing alkenyl group, and up to three of R ^{1 to} R ⁴ are branched alkyl groups, alkenyl groups, aryl groups or arylalkyl groups,
X ⁻ represents an organic or inorganic anion. ) 2. A negative charge toner for developing an electrostatic image comprising at least a binder resin, a colorant and a negative charge control agent, wherein the negative charge control agent is a quaternary phosphonium compound represented by the following general formula 2. A negatively charged toner for developing an electrostatic charge image, which comprises at least one salt compound. [Chemical 2] (In the formula, R ^{1 to} R ⁴ represent a hydrogen atom or an organic group, and at least one of R ^{1 to} R ⁴ may have a linking group and has 1 to 69 carbon atoms and 3 to 66 fluorine atoms. A linear or branched fluorine-containing alkyl group or a fluorine-containing alkenyl group, and up to three of R ^{1 to} R ⁴ are branched alkyl groups, alkenyl groups, aryl groups or arylalkyl groups,
X ⁻ represents an organic or inorganic anion. ) 3. A one-component developer composed of toner particles is supplied and carried on a developer carrier provided opposite to the electrostatic latent image carrier, and the electrostatic latent image is formed by the carried toner particles. In the developing method of developing, the toner particles contain a quaternary ammonium salt compound represented by the following general formula 1 and / or a quaternary phosphonium salt compound represented by the following general formula 2 as a negative charge control agent. And a developing method. [Chemical 1] (In the formula, R ^{1 to} R ⁴ represent a hydrogen atom or an organic group, and at least one of R ^{1 to} R ⁴ may have a linking group and has 1 to 69 carbon atoms and 3 to 66 fluorine atoms. A linear or branched fluorine-containing alkyl group or a fluorine-containing alkenyl group, and up to three of R ^{1 to} R ⁴ are branched alkyl groups, alkenyl groups, aryl groups or arylalkyl groups,
X ⁻ represents an organic or inorganic anion. ) [Chemical 2] (In the formula, R ^{1 to} R ⁴ represent a hydrogen atom or an organic group, and at least one of R ^{1 to} R ⁴ may have a linking group and has 1 to 69 carbon atoms and 3 to 66 fluorine atoms. A linear or branched fluorine-containing alkyl group or a fluorine-containing alkenyl group, and up to three of R ^{1 to} R ⁴ are branched alkyl groups, alkenyl groups, aryl groups or arylalkyl groups,
X ⁻ represents an organic or inorganic anion. ) 4. The developing method according to claim 3, wherein the surface of the developer carrying member is made of silicone rubber or silicone resin.